Study On The Soil Seed Bank Of Coal Gangue Piles In Datong

The potential and value of soil seed bank and topsoil in ecological restoration,biodiversity conservation and eco-environment manageme should not be underestimated.As the basis and potential greening material for ecological restoration,vegetation renewal and succession,the soil seed bank is irreplaceable and non-renewable resources in mining areas.So the study on the soil seed bank of mining areas has important theoretical and practical significance.Based on the basic principles of restoration ecology,this research takes the soil seed bank of coal gangue pile in different succession stages in Datong mining areas as the research object.Data collection,field survey and laboratory experiment were conducted to study the characteristics of soil seed bank in different succession stages,such as species composition,quantitative characteristics,distribution structure,species density,diversity,similarity and its relationship with soil fertility and aboveground vegetation.Main results were as follow:(1)446 seedlings of 24 species belonging to 9 families and 19 generas were germinated in different successional stages of the coal gangue pile soil seed bank;Compositae and Granimeae are the main families;Perennial herbs and Annual herbs are the main life form of the soil seed bank;In the process of succession,the number of plant germination,species families,generas and species tends to increase,and there is only one Subshrub specie(Artemisia sacrorum)in soil seed bank.(2)The seed density of soil seed bank varied from 835seeds/m2 to 2873seeds/m2 in different succession stages,is lower than the local natural environment(1388~9853seeds/m2);The density of soil seed bank was distrinct in different succession stages;Artemisia annua,Chloris virgate and Setaria viridis are the dominant species in soil seed bank.In the spatial distribution,seed germination mainly occurred in the 0-5cm soil layer(more than 50%),the soil seed bank has distinct vertical structure,with the increase of soil depth,and the number of seeds was decreased.With the process of succession,the proportion of seed density in 0-5cm soil layer was decreased,but 5-10 cm and 10-15 cm soil layer increased.(3)The species diversity of soil seed bank shows a regular pattern with the process of succession: Early,the species were diverse and evenly distributed;After that the seed bank species diversity decreased and the dominant species were outstanding;Finally,the species richness,diversity enhancement,dominant species status back down.The distrinct between soil seed banks in different soil layers was remarkable with the process of succession.The similarity coefficient of soil seed bank was gradually increasing with the process of succession.(4)The soil fertility of coal gangue pile was inferior.As time succession,the soil capacity of water and fertilizer retention increased gradually;There is no obvious regularity between the density of soil seed bank and the soil fertility.(5)Field survey of aboveground vegetation,18 families,36 generas and 39 species of plants were counted.Compositae and Granimeae plants are the main families and herbs are the main life form;the largest number of statistics are Eriophorum,Chloris virgate and Setaria viridis,and they occupied an important position.(6)The vegetation species significantly more than the number of soil seed bank species,is 1.625 times of the soil seed bank;Compositae and Granimeae plants are the main families of surface vegetation and soil seed bank,Annual and Perennial herbs are the main life form of surface vegetation and soil seed bank.Artemisia annua,Chloris virgate and Setaria viridis has high frequencies in the soil seed bank and surface vegetation;Cs similarity index between soil seed bank and vegetation is 0.28~0.49,similar degree was low,but in the process of succession,the similarities between soil seed bank and vegetation increased gradually,and the degree of similarity was enhance.